CFTR Function Restoration upon Elexacaftor/Tezacaftor/Ivacaftor Treatment in Patient-Derived Intestinal Organoids with Rare CFTR Genotypes.

Cystic fibrosis (CF) is caused by mutations in the Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene. The combination of the CFTR modulators elexacaftor, tezacaftor, and ivacaftor (ETI) enables the effective rescue of CFTR function in people with the most prevalent F508del mutation. However, the functional restoration of rare CFTR variants remains unclear. Here, we use patient-derived intestinal organoids (PDIOs) to identify rare CFTR variants and potentially individuals with CF that might benefit from ETI. First, steady-state lumen area (SLA) measurements were taken to assess CFTR function and compare it to the level observed in healthy controls. Secondly, the forskolin-induced swelling (FIS) assay was performed to measure CFTR rescue within a lower function range, and to further compare it to ETI-mediated CFTR rescue in CFTR genotypes that have received market approval. ETI responses in 30 PDIOs harboring the F508del mutation served as reference for ETI responses of 22 PDIOs with genotypes that are not currently eligible for CFTR modulator treatment, following European Medicine Agency (EMA) and/or U.S. Food and Drug Administration (FDA) regulations. Our data expand previous datasets showing a correlation between in vitro CFTR rescue in organoids and corresponding in vivo ppFEV1 improvement upon a CFTR modulator treatment in published clinical trials, and suggests that the majority of individuals with rare CFTR variants could benefit from ETI. CFTR restoration was further confirmed on protein levels using Western blot. Our data support that CFTR function measurements in PDIOs with rare CFTR genotypes can help to select potential responders to ETI, and suggest that regulatory authorities need to consider providing access to treatment based on the principle of equality for people with CF who do not have access to treatment.

Forskolin-induced organoid swelling is associated with long-term cystic fibrosis disease progression.

RATIONALE: Cystic fibrosis (CF) is a monogenic life-shortening disease associated with highly variable individual disease progression which is difficult to predict. Here we assessed the association of forskolin-induced swelling (FIS) of patient-derived organoids with long-term CF disease progression in multiple organs and compared FIS with the golden standard biomarker sweat chloride concentration (SCC). METHODS: We retrieved 9-year longitudinal clinical data from the Dutch CF Registry of 173 people with mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Individual CFTR function was defined by FIS, measured as the relative size increase of intestinal organoids after stimulation with 0.8 µM forskolin, quantified as area under the curve (AUC). We used linear mixed-effect models and multivariable logistic regression to estimate the association of FIS with long-term forced expiratory volume in 1 s % predicted (FEV1pp) decline and development of pancreatic insufficiency, CF-related liver disease and diabetes. Within these models, FIS was compared with SCC. RESULTS: FIS was strongly associated with longitudinal changes of lung function, with an estimated difference in annual FEV1pp decline of 0.32% (95% CI 0.11-0.54%; p=0.004) per 1000-point change in AUC. Moreover, increasing FIS levels were associated with lower odds of developing pancreatic insufficiency (adjusted OR 0.18, 95% CI 0.07-0.46; p<0.001), CF-related liver disease (adjusted OR 0.18, 95% CI 0.06-0.54; p=0.002) and diabetes (adjusted OR 0.34, 95% CI 0.12-0.97; p=0.044). These associations were absent for SCC. CONCLUSION: This study exemplifies the prognostic value of a patient-derived organoid-based biomarker within a clinical setting, which is especially important for people carrying rare CFTR mutations with unclear clinical consequences.

A new era for people with cystic fibrosis.

Cystic fibrosis is the most prevalent inherited disease caused by a defect in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The impaired electrolyte homeostasis caused by the mutated or absent protein leads to symptoms in multiple organ systems. However, the pulmonary manifestation with chronic infections and eventually respiratory failure remains the most important threat. Until one decade ago, only symptomatic treatment was available. However, since 2012, different combinations of CFTR modulators are available for people with cystic fibrosis (pwCF) that carry different mutations. The advent of these drugs has impressively changed life expectancy and quality of life in people with cystic fibrosis and raised new challenges regarding long-term complications and tapering of conventional therapies.Conclusion: In this review, we provide an update on the latest developments around diagnostics, treatment, and prognosis of pwCF. What is Known: • Cystic fibrosis is an incurable and life-shortening disease asking for life-long symptomatic treatment. • Three combination CFTR modulating drugs has gained marked approval over the last 10 years. What is New: • The emerge of new (modulating) therapies contribute to the increasing life expectancy. • A high unmet need to develop new therapies for people with CF who cannot access or benefit from these drugs remains. This review gives an update on the current status.

Centralized intestinal organoid generation is a feasible and safe approach for personalized medicine as demonstrated in the HIT-CF Europe Organoid Study.

BACKGROUND: Patient-derived intestinal organoids (PDIOs) show great potential as in vitro drug testing platform for personalised medicine in Cystic Fibrosis and oncology. PDIOs can be generated by culturing adult stem cells obtained through rectal forceps biopsy or suction biopsy, but the safety of these procedures and the success rates of generating organoids after shipment to a centralized lab using these procedures has not been studied in this context. We here report the safety and success rates of both biopsy procedures and the subsequent generation of PDIOs in the international multicentre HIT-CF Organoid Study. METHODS: 502 biopsy procedures were conducted, on 489 adult people with Cystic Fibrosis from 33 different hospitals across 12 countries. Depending on the preference of the hospital, either rectal forceps biopsies or suction biopsies were obtained and internationally shipped to a central laboratory for organoid generation. RESULTS: No adverse events were reported for 280 forceps biopsy procedures, while 222 rectal suction biopsy procedures resulted in 2 adverse events, namely continued bleeding and a probably nonrelated gastroenteritis. The success rate of organoid generation from all biopsies was 95%, and the main reason for failure was insufficient sample viability (3.2%). CONCLUSION: Our results indicate that both rectal suction biopsy and forceps biopsy procedures are safe procedures. The high success rates of PDIO generation from the obtained tissue samples demonstrate the feasibility of the organoid technology for personalised in vitro testing in an international setting.

High-throughput functional assay in cystic fibrosis patient-derived organoids allows drug repurposing.

Background: Cystic fibrosis (CF) is a rare hereditary disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Recent therapies enable effective restoration of CFTR function of the most common F508del CFTR mutation. This shifts the unmet clinical need towards people with rare CFTR mutations such as nonsense mutations, of which G542X and W1282X are most prevalent. CFTR function measurements in patient-derived cell-based assays played a critical role in preclinical drug development for CF and may play an important role to identify new drugs for people with rare CFTR mutations. Methods: Here, we miniaturised the previously described forskolin-induced swelling (FIS) assay in intestinal organoids from a 96-well to a 384-well plate screening format. Using this novel assay, we tested CFTR increasing potential of a 1400-compound Food and Drug Administration (FDA)-approved drug library in organoids from donors with W1282X/W1282X CFTR nonsense mutations. Results: The 384-well FIS assay demonstrated uniformity and robustness based on coefficient of variation and Z'-factor calculations. In the primary screen, CFTR induction was limited overall, yet interestingly, the top five compound combinations that increased CFTR function all contained at least one statin. In the secondary screen, we indeed verified that four out of the five statins (mevastatin, lovastatin, simvastatin and fluvastatin) increased CFTR function when combined with CFTR modulators. Statin-induced CFTR rescue was concentration-dependent and W1282X-specific. Conclusions: Future studies should focus on elucidating genotype specificity and mode-of-action of statins in more detail. This study exemplifies proof of principle of large-scale compound screening in a functional assay using patient-derived organoids.

Development and validation of a novel personalized electronic patient-reported outcome measure to assess quality of life (Q-LIFE): a prospective observational study in people with Cystic Fibrosis.

Background: Generic and disease-specific patient-reported outcome measures (PROMs) may lack relevance and sensitivity on a patient-level in chronic diseases with differential disease expression and high individual variability, such as Cystic Fibrosis (CF). This study aimed to develop and validate a novel personalized electronic PROM (ePROM) that captures relevant aspects of quality of life in individuals with CF. Methods: The Q-Life app was developed as a short personalized ePROM to assess individual quality of life. Psychometric properties were assessed in a single-center cross-sectional study between September 2019 and September 2021 and in a prospective cohort study between September 2021 and September 2022. Findings: Combined studies included 223 participants (median age: 24 years, IQR: 19.0-32.5 years, range: 12.0-58.0 years). Internal consistency (Cronbach's alpha: 0.83-0.90) and test-retest reliability (intraclass correlation coefficient: 0.90; 95% CI: 0.65-0.92; p < 0.001) of quality of life (Q-Life) scores were strong. Q-Life scores were associated with overall Cystic Fibrosis Questionnaire-Revised (CFQ-R) scores (ρ = 0.71; p < 0.001), CFQ-R respiratory domain scores (ρ = 0.57; p < 0.001) and forced expiratory volume in 1s (ρ = 0.41; p < 0.001). Furthermore, Q-Life scores improved from 65.0 (IQR: 45.0-63.3) at baseline to 84.2 (IQR: 75.0-95.0) and 87.5 (IQR: 75.0-100.0) after 3 and 6 months of elexacaftor/tezacaftor/ivacaftor treatment (change: 20.8; 95% CI: 17.5-25.0; p < 0.001), comparable to CFQ-R respiratory domain scores (change: 22.2, 95% CI: 19.4-25.0, p < 0.001). Interpretation: The Q-Life app is a reliable, valid and sensitive personalized ePROM to measure all aspects of quality of life that really matter to individuals with Cystic Fibrosis. This patient-centered approach could provide important advantages over generic and disease-specific PROMs in the era of personalized medicine and value-based healthcare. Funding: Dutch Cystic Fibrosis Foundation, Health-Holland.

Impaired SARS-CoV-2 specific T-cell response in patients with severe COVID-19.

Cellular immune responses are of pivotal importance to understand SARS-CoV-2 pathogenicity. Using an enzyme-linked immunosorbent spot (ELISpot) interferon-γ release assay with wild-type spike, membrane and nucleocapsid peptide pools, we longitudinally characterized functional SARS-CoV-2 specific T-cell responses in a cohort of patients with mild, moderate and severe COVID-19. All patients were included before emergence of the Omicron (B.1.1.529) variant. Our most important finding was an impaired development of early IFN-γ-secreting virus-specific T-cells in severe patients compared to patients with moderate disease, indicating that absence of virus-specific cellular responses in the acute phase may act as a prognostic factor for severe disease. Remarkably, in addition to reactivity against the spike protein, a substantial proportion of the SARS-CoV-2 specific T-cell response was directed against the conserved membrane protein. This may be relevant for diagnostics and vaccine design, especially considering new variants with heavily mutated spike proteins. Our data further strengthen the hypothesis that dysregulated adaptive immunity plays a central role in COVID-19 immunopathogenesis.

Long-term effectiveness of dual CFTR modulator treatment of cystic fibrosis.

Background: Although short-term efficacy of lumacaftor/ivacaftor and tezacaftor/ivacaftor is clearly established in clinical trials, data on long-term effectiveness is limited. This registry-based cohort study assessed real-world longitudinal outcomes of F508del-homozygous people with cystic fibrosis (pwCF) ≥12 years, up to 3 years after the introduction of dual cystic fibrosis transmembrane conductance regulator (CFTR) modulators. Methods: Annual data (2010-2019) were retrieved from the Dutch Cystic Fibrosis Registry. Longitudinal trends of per cent predicted forced expiratory volume in 1 s (FEV1 % pred) decline, body mass index (BMI), BMI Z-score and intravenous antibiotic treatment duration before and after CFTR modulator initiation were assessed with linear and negative binomial mixed models. Results: We included 401 participants (41.9% female, baseline age 24.5 years (IQR 18.0-31.5 years), baseline mean±sd FEV1 70.5±23.4% pred). FEV1 decline improved from -1.36% pred per year to -0.48% pred per year after modulator initiation (change: 0.88% pred, 95% CI: 0.35-1.39%, p=0.001). This change was even 1.40% pred per year (95% CI: -0.0001-2.82%, p=0.050) higher in participants with baseline FEV1 <40% pred. In adults, annual BMI trend was not altered (change: 0.10 kg·m-2·year-1, 95% CI:-0.01-0.21, p=0.079). Annual BMI Z-score in children reversed from -0.08 per year before modulator treatment to 0.06 per year afterwards (change: 0.14 per year, 95% CI: 0.06-0.22, p<0.001). Intravenous antibiotic treatment duration showed a three-fold reduction in the first year after modulator initiation (incidence rate ratios (IRR): 0.28, 95% CI: 0.19-0.40, p<0.001), but the annual trend did not change in the subsequent years (IRR: 1.19, 95% CI: 0.94-1.50, p=0.153). Conclusion: Long-term effectiveness of dual CFTR modulator therapies on FEV1 decline, BMI and intravenous antibiotic treatment duration is less pronounced in a real-world setting than in clinical trials and varies considerably between pwCF and different baseline FEV1 levels.

Prediction of Real-World Long-Term Outcomes of People with CF Homozygous for the F508del Mutation Treated with CFTR Modulators.

The clinical response to cystic fibrosis transmembrane conductance regulator (CFTR) modulators is variable within people with cystic fibrosis (pwCF) homozygous for the F508del mutation. The prediction of clinical effect in individual patients would be useful to target therapy to those who would benefit from it. A multicenter observational cohort study was conducted including 97 pwCF (F508del/F508del), who started lumacaftor/ivacaftor (LUM/IVA) treatment before June 2018. In order to assess the associations of individual in vivo and in vitro biomarkers with clinical outcomes, we collected clinical data regarding sex, age, and sweat chloride concentration (SwCl) at baseline and after six months of LUM/IVA; the percent predicted forced expiratory volume in 1 s (ppFEV1) and the number of pulmonary exacerbations (PEx) during the three years before up to three years after modulator initiation; and the forskolin-induced swelling (FIS) responses to LUM/IVA, quantified in intestinal organoids. On a group level, the results showed an acute change in ppFEV1 after LUM/IVA initiation (2.34%, 95% CI 0.85-3.82, p = 0.003), but no significant change in annual ppFEV1 decline in the three years after LUM/IVA compared to the three years before (change: 0.11% per year, 95%CI: -1.94-2.19, p = 0.913). Neither of these two outcomes was associated with any of the candidate predictors on an individual level. The median number of pulmonary exacerbations (PEx) per patient year did not significantly change in the three years after LUM/IVA compared to the years before (median: 0.33/patient year, IQR: 0-0.67 before vs. median: 0/patient year, IQR: 0-0.67 after p = 0. 268). The PEx rate after modulator initiation was associated with the PEx rate before (IRR: 2.26, 95%CI: 1.67-3.08, p < 0.001), with sex (males vs. females IRR: 0.36, 95%CI: 0.21-0.63, p = 0.001) and with sweat chloride concentration (SwCl) at baseline (IRR: 0.96, 95%CI: 0.94-0.98, p = 0.001). The change in SwCl was also significant (-22.9 mmol/L (95%CI: -27.1--18.8, p < 0.001) and was associated with SwCl at baseline (-0.64, 95%CI: -0.90--0.37, p < 0.001) and with sex (males vs. females 8.32, 95%CI: 1.82-14.82, p = 0.013). In conclusion, ppFEV1 decline after CFTR modulator initiation remains difficult to predict in individual patients in a real-world setting, with limited effectiveness for double CFTR modulator therapies. The PEx rate prior to CFTR modulator treatment initiation, sex and SwCl at baseline could be potential predictors of long-term PEx rate and of changes in SwCl after modulator initiation.

CRISPR-Based Adenine Editors Correct Nonsense Mutations in a Cystic Fibrosis Organoid Biobank.

Adenine base editing (ABE) enables enzymatic conversion from A-T into G-C base pairs. ABE holds promise for clinical application, as it does not depend on the introduction of double-strand breaks, contrary to conventional CRISPR/Cas9-mediated genome engineering. Here, we describe a cystic fibrosis (CF) intestinal organoid biobank, representing 664 patients, of which ~20% can theoretically be repaired by ABE. We apply SpCas9-ABE (PAM recognition sequence: NGG) and xCas9-ABE (PAM recognition sequence: NGN) on four selected CF organoid samples. Genetic and functional repair was obtained in all four cases, while whole-genome sequencing (WGS) of corrected lines of two patients did not detect off-target mutations. These observations exemplify the value of large, patient-derived organoid biobanks representing hereditary disease and indicate that ABE may be safely applied in human cells.

Changes in Timing and kinematics of goal directed eye-hand movements in early-stage Parkinson's disease.

OBJECTIVE: Many daily activities involve intrinsic or extrinsic goal-directed eye and hand movements. An extensive visuomotor coordination network including nigro-striatal pathways is required for efficient timing and positioning of eyes and hands. The aim of this study was to investigate how Parkinson's disease (PD) affects eye-hand coordination in tasks with different cognitive complexity. METHODS: We used a touch screen, an eye-tracking device and a motion capturing system to quantify changes in eye-hand coordination in early-stage PD patients (H&Y < 2.5) and age-matched controls. Timing and kinematics of eye and hand were quantified in four eye-hand coordination tasks (pro-tapping, dual planning, anti-tapping and spatial memory task). RESULTS: In the pro-tapping task, saccade initiation towards extrinsic goals was not impaired. However, in the dual planning and anti-tapping task initiation of saccades towards intrinsic goals was faster in PD patients. Hand movements were differently affected: initiation of the hand movement was only delayed in the pro-tapping and dual planning task. Overall, hand movements in PD patients were slower executed compared to controls. INTERPRETATION: Whereas initiation of saccades in an extrinsic goal-directed task (pro-tapping task) is not affected, early stage PD patients have difficulty in suppressing reflexive saccades towards extrinsic goals in tasks where the endpoint is an intrinsic goal (e.g. dual planning and anti-tapping task). This is specific for eye movements, as hand movements have delayed responses in the pro-tapping and dual planning task. This suggests that reported impairment of the dorsolateral prefrontal cortex in early-stage PD patients affects only inhibition of eye movements. We conclude that timing and kinematics of eye and hand movements in visuomotor tasks are affected in PD patients. This result may have clinical significance by providing a behavioral marker for the early diagnosis of PD.

Visuomotor impairment in early-stage Alzheimer's disease: changes in relative timing of eye and hand movements.

Although memory complaints are one of the first clinical symptoms in patients with Alzheimer's disease (AD), damage to the parietal lobe, a key structure in the visuomotor coordination network, was recently identified in early-stage AD. The aim of this study was to quantify visuomotor coordination in patients with probable AD and to compare their visuomotor performance with controls using five eye-hand coordination tasks of variable complexity. Eye and hand movements were measured in 16 AD patients and 18 controls. The measurement setup consisted of a touch screen, an eye-tracking device, and a motion capturing system. We investigated eye-hand coordination by quantifying absolute and relative latencies of eye and hand movements and by analyzing eye and hand kinematics. We found that AD patients need significantly more time to initiate and execute goal-directed hand movements. AD patients are also unable to suppress reflexive eye and, to a lesser extent, hand movements. Furthermore, AD patients use a stepwise approach of eye and hand movements to touch a sequence of stimuli, whereas controls more often show an anticipatory approach. The impairments in reflex suppression of eye and hand movements, and changes in relative timing of eye-hand coordination, in AD patients support the notion that cortical networks involving the posterior parietal cortex are affected at an early disease-stage. It also suggests that the problems of AD patients to perform daily activities that require eye-hand coordination are not only caused by cognitive decline, but also by degeneration of neural networks involved in visuomotor coordination.